Matthews pounced. "He does? Are you speaking for him now? Are you speaking for Donald Trump tonight, on live television? Are you saying for him, I'm saying he's about to buckle and say finally, that Barack Obama is a legitimate President of the United States?"

Giuliani sputtered and spit nonsense about how Trump "got him to finally produce the birth certificate," before Chris Matthews had enough of that and shut it straight down, returning to the question of Trump's birtherism.

"Can you commit to your candidate saying within the next 24 hours that President Obama's a legitimate president? Can you commit for him that he will say that?," he pressed.

After Giuliani once again tried to get back to claiming it was Hillary Clinton who started the rumor, and another back-and-forth with ridiculous claims on Giuliani's part, Chris had finally had enough.

"Let me tell you, there's no record at all of that. We checked this before you came on because one of our senior producers thought you might say this, There is absolutely no record ever of Hillary Clinton or anyone in her campaign ever saying that President Obama is not legitimate."

"We are ending this now because we are spending a lot of time on it but I think it is important. you say this president is the legitimately elected President of the United States and you say your candidate agrees with you," he hammered.

Concluding the interview, Matthews went on. "We are trying to pick the next president, not review the birth of the current president. Thank you, Mayor Rudy Giuliani."

This is where Rudy lost it entirely, and said something he's going to wish he hadn't said.

"Let's talk about the next president being someone who would be prosecuted if she wasn't a Clinton.," Rudy ranted.